<template>
  <div>
    <van-list
      :class="{
        'art-cmt-container-1': isShow,
        'art-cmt-container-2': !isShow,
      }"
      v-model="loading"
      :finished="finished"
      finished-text="没有更多了"
      :immediate-check="false"
      @load="onLoad"
    >
      <!-- 评论列表 -->
      <div v-for="item in comment" :key="item.com_id" class="cmt-list">
        <!-- 评论的 Item 项 -->
        <div class="cmt-item">
          <!-- 头部区域 -->
          <div class="cmt-header">
            <!-- 头部左侧 -->
            <div class="cmt-header-left">
              <img :src="item.aut_photo" alt="" class="avatar" />
              <span class="uname">{{ item.aut_name }}</span>
            </div>
            <!-- 头部右侧 -->
            <div class="cmt-header-right">
              <!-- 已点赞显示这个 -->
              <van-icon
                name="like"
                size="0.42666666rem"
                color="red"
                v-if="item.is_liking"
                @click="isLiking(false, item)"
              />
              <!-- 未点赞显示这个 -->
              <van-icon
                name="like-o"
                size="0.42666666rem"
                color="gray"
                v-else
                @click="isLiking(true, item)"
              />
            </div>
          </div>
          <!-- 主体区域 -->
          <div class="cmt-body" v-html="item.content"></div>
          <!-- 尾部区域 -->
          <div class="cmt-footer">{{ formatDate(item.pubdate) }}</div>
        </div>
      </div>
    </van-list>
    <!-- 底部添加评论区域 - 1 -->
    <div class="add-cmt-box van-hairline--top" v-if="isShow">
      <van-icon name="arrow-left" size="0.48rem" @click="$router.back()" />
      <div class="ipt-cmt-div" @click="sendComment">发表评论</div>
      <div class="icon-box">
        <van-badge :content="total || ''" max="99">
          <van-icon
            name="comment-o"
            size="0.53333334rem"
            @click="commentTotal"
          />
        </van-badge>
        <van-icon name="star-o" size="0.53333334rem" />
        <van-icon name="share-o" size="0.53333334rem" />
      </div>
    </div>

    <!-- 底部添加评论区域 - 2 -->
    <div class="cmt-box van-hairline--top" v-else>
      <textarea
        placeholder="友善评论、理性发言、阳光心灵"
        v-fofo
        @blur="comeBack"
        v-model.trim="contentText"
      ></textarea>
      <van-button
        type="default"
        :disabled="contentText.length === 0"
        @click="sendFn"
        >发布</van-button
      >
    </div>
  </div>
</template>

<script>
import {
  getCommentApi,
  likeCommentApi,
  dislikeCommentApi,
  sendCommentAPI
} from '@/api'
import dayjs from 'dayjs'
import 'dayjs/locale/zh-cn' // import locale
import * as relativeTime from 'dayjs/plugin/relativeTime'

dayjs.locale('zh-cn') // use locale
dayjs().format()
dayjs.extend(relativeTime)
export default {
  data () {
    return {
      comment: [],
      isShow: true,
      total: 0,
      contentText: '',
      loading: false,
      finished: false,
      lastId: null
    }
  },
  created () {
    this.getCommentFn()
  },
  props: ['artId'],
  methods: {
    async getCommentFn () {
      const res = await getCommentApi({
        type: 'a',
        source: this.artId,
        offset: this.lastId
      })
      // 如果请求不到结果,就将finish切换位true
      if (res.data.data.results.length === 0) this.finished = true
      this.comment = [...this.comment, ...res.data.data.results]
      this.total = res.data.data.total_count
      this.lastId = res.data.data.last_id
      // 关闭loading
      this.loading = false
    },
    // 当触发下拉时,调用这里
    onLoad () {
      if (this.comment.length > 0) {
        this.getCommentFn()
      }
    },
    formatDate (data) {
      var a = dayjs()
      var b = dayjs(data)
      const c = a.to(b) // in 2 years
      return c
    },
    // 点击切换红心
    async isLiking (bool, obj) {
      if (bool) {
        // 切换红心
        // 点赞
        obj.is_liking = true
        // 给文章点赞
        await likeCommentApi(obj.com_id)
      } else {
        // 切换白心
        // 取消点赞
        obj.is_liking = false
        await dislikeCommentApi(obj.com_id)
      }
    },
    // 点击呼出输入框
    sendComment () {
      // 点击呼出输入框,并且自动聚焦
      this.isShow = false
      // 滚动至当前页最底部
      // 发现没有效果
      // 原因:vue渲染dom是一个promise ,是异步的,所以需要等待异步渲染完毕再执行下面的程序
      this.$nextTick(() => {
        if (this.comment.length > 0) {
          const list = document.querySelectorAll('.cmt-list')
          list[list.length - 1].scrollIntoView({ behavior: 'smooth' })
        }
      })
    },
    // 失去焦点返回原样
    comeBack () {
      setTimeout(() => {
        this.isShow = true
      })
    },
    // 评论总条数,点击跳转到第一条
    commentTotal () {
      document
        .querySelector('.like-box')
        .scrollIntoView({ behavior: 'smooth' })
    },
    // 点击发送评论
    async sendFn () {
      await sendCommentAPI({
        target: this.artId,
        content: this.contentText
      })
      // 在点击的一瞬间,v-if生效,立即销毁了dom所以不生效
      // 将评论列表清空,重置offset
      this.comment = []
      this.lastId = null
      this.getCommentFn()
      // 滚动到上面
      document
        .querySelector('.like-box')
        .scrollIntoView({ behavior: 'smooth' })
    }
  }
}
</script>

<style scoped lang="less">
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}
/*美化 - 文章详情 - 底部的评论页面 */
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
